I've been helping a buddy install a system in his 2016 Jeep Wrangler JK. I finally have enough pics to start a build log, so I'll be loading all of them up over the next couple weeks.
The requirements were simple: he wanted (4) 8's or nothing at all. Silly? Maybe; but we met the requirements and hope to be banging before the end of the year
The stock sub (an 8x10) has 4 voice coils
Ran some numbers in TermLab at first, but then switched the design over to WinISD. Came up with this size enclosure:
That router feels good man
Went with PSI-8's with High Performance suspension for 600Wrms per sub
We were jammin some of that good techno
The original plan was to have a few tube ports, but I had a hunch that they were too small. Thats about the time that Triticum came out with his port velocity calculator, and I realized the port velocities with these small ports would give me the tuning we were wanting, but also gave us almost 100 m/s port velocity (yikes!)
Then the design changed to have a properly sized port attached to the back panel, bringing the velocities down to around 25-30 m/s
I didnt really trust my kerf skills yet
More pics coming tomorrow. Thanks for looking!

Alright, so I have designed my box. 1.72 sealed/3.0 ported. 8 inch aeroport tuned to 42hz. Sub is a single zv3 15, amp as of now is a sundown 1500 (I plan on upgrading to over 3k soon). I have drawn out some box sketches and played around in WinISD and Torres box calculator. Do the box numbers (cft, tuning, port size) sound right? I know theres a lot to play around with when it comes to box designs. I know some people will think "Just build it and see if it sounds good", but Im only 18, so I dont have all the money in the world, so if I spend this money on building the box and it doesnt turn out well, im just out that amount of money. I just want to hear some opinions on the box, good or bad. I've designed plenty of sealed/ported boxes, but just now getting into the 4th order scene. Appreciate the help

Hello all, been a while since I have posted here.
I have been out of the audio world for a few years, but I picked up a 4th order box off facebook recently that was built specifically for my 2001 Chevy Tahoe. Got it with all the trim pieces for $150.. I couldn't pass it up. I have attached a few photos if anyone is curious to see what it looks like, they arent the best but you'll get the idea.
I have tried searching this forum and google but couldn't find any real specific answers. I am trying to figure out what subs would work best in a 4th order application, I have found that High Qts and low Fs is what I am looking for, but I do not know any specific numbers as far as whats considered to be a "high" Qts number or a "low" Fs number that I should be trying to stay within. Also, any other major factors to consider aside from recommended enclosure size?
I am trying to keep this (sort of) a budget build and looking to spend around $100 per sub and have the subs on around 3-4k rms total. I was thinking I would go with the D2 HDS2 15s by Soundqubed as they are $104 a piece. Is this a decent sub for a 4th order application? Fs is 28.93 and Qts is .572.
I am not set on this sub, and am currently searching through local facebook groups daily for some used subwoofer options. I know box volume can also play a factor in deciding subs, I dont have the exact dimensions currently but can get them if needed. I have no issue determining the box volume and reading whats recommended for the subwoofer as far as box volume goes. Mainly the Qts and Fs is my concern.
Any suggestions would be greatly appreciated, Thank you!

Parts of this log will be copied over from where I currently have it on CACO I just wanted to share it here since I'm a new member started working on it in early December it's a slow project.
Well for a long time I'd been trying to sell my Grand Prix and just couldn't seem to get rid of it. Guy offered to trade me a Jeep and I've always wanted a jeep so despite the Jeep having 250K miles I took him up on it. The interior is super clean and the outside is in good shape as well. Rockers are a little rusty but that's a Michigan Jeep thing.The plan for the Jeep is for it to be a winter beater/audio ride. Trying to keep the salt off of my Duramax. As far as the audio goes planning a B Pillar 4th for 4 18's on roughly 8k. From my rough measurements today I will have 46 cubes gross to work with. Progress will be kind of slow as I'm currently laid off. The goal is to be finished by whenever the first show in Michigan is. Will be primarily competing in IASCA and ISPLL. I always wanted a cool build log name even though it's lame.Builds that I'll be pulling some inspiration from include, Galen Winesette's Jeep, Chris Russ' Jeep, and Don's TDH Jeep.Tenative Equipment List:Electrical2 Mechman 320's Externally RegulatedFull Throttle Group 31 for under the hoodJY Lithium (Leaning towards 80 AH)Welding Cable 2/0 (Lots of it)ILL Customz Battery Terminals Clarion CZ702 already have (unless I find a great deal on an 80 PRS)4 Cascade Omega Neo 18's (building motors like Robs, PSI recones likely)Amp must be under 8K class restrictions (Flatline B2A, M1S, AB 750.1)Not sure on mids probably Crescendo PWX's or McLaren4 Channels (Really thinking PPI 900.4's)Other:Welder (Really want a lincoln Power Mig 210 with the Tig torch)300 or so feet of steel 1x2 tubingAir Bags of some sort I'm sureBHE 4th order design or something similarVolt Meters
Out with the old:
In with the new:
Like I said it's clean:
Going to be a shame to gut it from the B-Pillar back:
Steel sets:

So I have been trying to calculate my first 4th order for 2 orion hcca 10s. I have started with having a seperate sealed chamber for each sub with 0.625 cuft each and a common ported chamber of 2.5 cuft tuned to 45hz. I was just wondering how much port area I would need? Also if the airspace would be fine? Also I went for a 2:1 ratio since that was pretty common, what would be the advantage of going to a bigger ratio like a 3:1? Ive heard these subs like smaller enclosures so I didnt want to get to big. Thanks!

I'm looking at building my first 4th order for a sundown zv4 rev2 15"d2. I have experience building custom boxes but have never built a bandpass. I'm not sure on what ratio to go with. I like lows but would really like something musical. It's going in a extended cab f150 powered by a shark [email protected] Could someone tell me how many cubes for the sealed and ported side and how many sqin my port should be and what's the best to tune it at? Any info is greatly appreciated!

Ok I have a 04-08 supercrew f150 with a seat lift kit installed. Will be putting in 2 skar zvx 8d2. With the 4th order box right now I have 1:1 ^3 sealed to ported. I have been doing lots of studying on Pollyfill. There is a proven method of using IM-SG SMD to measure the gain of ^3 with adding Pollyfill to a box the video was done by demore engineering. They added Pollyfill to a box and added 20% more box volume by adding Pollyfill. the problem is I don't know how much Pollyfill they added to achieve 20% volume increase. So what I'm trying to accomplish is after adding Pollyfill to sealed section having my box volume 1.3^3 for both subs giving me perfect sealed size for the subs which will give me closer to 1:1.5 ratio of sealed and ported then Pollyfill the ported section with the end result close to 1:2 ratio of sealed to ported. I've had multiple people tell me I'm crazy but numbers are saying it can be done if someone knows how much Pollyfill= ^3 % gain.
Thanks in advance!!!

I'm trying to design a 4th order for my Dodge charger, but I'm not familiar with bassbox pro. Just wondering how everything looks. I found a design on here that was almost exactly what I needed, but not enough space on vented side so I did a little tweaking. Going for 45-50hz with 2 cubes on sealed and 4 for ported side, for a 2:1 ratio. Not everything is filled in, like fb or f3, but just wondering if it seems solid. I couldn't put the contraltos in as drivers so that it will tell me everything, cause I couldn't get the driver list to update, it kept having an error.

Im really curious if you guys were going to build a van with a big setup (160+) for demos, to be musical around town etc. The van has to look good and still be very very driveable.
What type of van would you use and why?
Also would like to know what your favourite vans are that are currently competing or have in the past? Favourite by looks, favourite by their setup, or favourite because a mixture of both.
The more pics the merrier....
Thanks for your time

Hey! I'm working on a build log for my friends box that I'm designing, and I just wanted some who's designed some of these (especially isobaric) to take a gander.
I wrote my own 4th order calculator in Java and posted it before I figured out there already was one online (fail). The specs are as follows:
Enclosure type: Isobaric 4th Order Bandpass
Subwoofers: 2 SoundQubed HDS-2.110 600WRMS
F(s): 31.63 Hz
Q(ts): 0.519
V(as): 1.97 ft^3
Vf: 0.52 ft^3
Vr: 1.101 ft^3
Qbp: 0.71
S Factor: 0.7
Fb: 43.53 Hz
Desired F3(L): 26.8 Hz
Passband: 26.8 - 70.72 Hz
Gain: 0 dB
Also the port specs were kind of crazy. The minimum size was 11.24" diameter and 78.84" long. I'd like a shorter port but the only way to do that is decrease diameter which increases air speed and might cause port chuffing.
Thanks a ton!!!

I was reading up on 6th order bandpass boxes and I ran across some patents. I found a lot of interesting design information in these patents, but no calculations. Whats the point you ask? To understand better how bandpass boxes function. Knowledge is power.
Most of the patents have a lot of blah blah blah near the beginning of each patent since justifying the patent is first and foremost. Somewhere past halfway, each patent lists some design tips, tricks, rules, etc that are great and thats where the interesting portions begin.
I recommend to have the attached pictures (at the beginning of the patent) opened on a second screen so that you can quickly reference the numbers identifying each component and its importance in each system.
4th order: https://www.google.com/patents/US2689016
Parallel tuned 6th order (Bose): https://www.google.com/patents/US4549631
Series tuned 6th order: https://www.google.com/patents/US4875546
Series and parallel-series tuned Nth order (8th and higher): https://www.google.com/patents/US7103193
Helmholtz Resonance, the concept that drives ported enclosures and all 4th, 6th, etc enclosures: https://en.wikipedia.org/wiki/Helmholtz_resonance
I've been reading through these for a few days now trying to understand whats going on with these more complicated arrangements and I think some of you will benefit from the information in these patents. Enjoy.

I aint new in here, but we don't really see such kinda installs here in India. I know walled setups in other countries are common but here in India it is relatively new.
Some of you folks might have checked my earlier build log posted here
http://www.stevemeadedesigns.com/board/topic/151241-2-fi-sp4s-in-a-ford-in-india/
I was using 2 FI SP4 15"s in a ported enclosure in boot of a SUV and managed to do a hairtrick. A vid can be seen here
http://www.youtube.com/watch?v=QO7nID88yJQ&feature=player_embedded
Was already bored of the setup and wanted to try something new..
Went through a thread on CACO regarding 4th orders and decided to try one of those for SP4's (Got impressed by vids posted by soundstreamsilverado), Took his suggestions regarding the enclosure and that's how it all started.
Once again the ride in which the setup was done..

Hello fellow bassheads! This is the build log for my car, the Kickin' Cruiser. The builds in this car started in 2010, and have changed several times since then. But in Dec. 2011 I decided to go big or go home, so I started planning this build for the final install. Actually got started about a month later, and have jumped around, way out of order. And I had to put it on hold for over 6 months for the birth of my newest son, T.J. (Trent Jr.) But I just keep pushing forward, with my goal of having a ground pounder PT still very much alive! So anyway, here we go. Much of this will be a repost, since I had a build log before, it just got messed up by facebook. I will attempt to keep it all in the correct order. The car is a 2002 Chrysler PT Cruiser that I bought a few years ago, and fell in love with ever since. Best car I have ever owned! And a while back, I decided to split the build into stages, so that it wouldn't seem so over-whelming, and so it would be easier to navigate through. So here is the plan for the different stages: Stage 1 - Initial instal Stage 2 - Fiberglass and accessories (Learning Stage) V.2 Stage 3 - Dash, doors, and a 4th order wall. (Time to get serious stage!) Stage 4 - Rims. body, and paint Stage 5 - Engine/ drive-train (performance mods) For this stage, we will be focusing on the interior of the car. We will build new custom door panels, dash panel, change all of the interior color from light brown/ dark brown to grey/ black. I'll also be Installing new carpet front to back, as well as building a new headliner. We will finish it off with new seats. Basically the whole inside of the car is getting a make-over!!! Oh and how could I forget? I'll be building a 4th order wall for 4 custom Solo X 15's (which I will build myself), to run off 2 DC5.0K's. Goals are mid 50's on music, and nasty hair tricks on demand. So here we go!!!!

https://scontent-atl3-1.xx.fbcdn.net/v/t1.0-9/13322194_1044872515596851_1106270700946616662_n.jpg?oh=6a5a640a7b1675fa1cddeb15a29cdb4d&oe=57EC3928
I am wanting to build something like this but can not find any info.
Size - Does not matter (2 seater Mountaineer gutted)
I have
(6) 8" mid bass
(2) 6" 3 way component
(2) 5.25 3 way component
AND 1 hybrid 15" Sundown Audio ZV3 Soft materials using DB Platinum Series 15 hardware
I will be running 2000 watts rms

I'm almost done with my new system. I have 4 cvr dual 4ohm 15s for right now. I have a QZA4100D pushing them and everything is wired down to .5 ohm. I'm waiting on wires to come in so I can upgrade my old ones.

Hello Everyone, Introduction first: My name is Kaleb Carter, I am a 19 year old College Student at University of North Florida. I work full time for Florida Blue as well as being a full time Mechanical Engineering Student. I live in the dorms so I only get to work on my build on the weekends in my dad's garage when I'm not too bogged down with work. I drive a 2002 Ford F-150 Supercrew that I had been saving up for since I was about 8 working for my dad cutting grass, cleaning houses, being a farmhand,doing landscaping, etc. It was paid off the day I had the keys in my hand. Also, I pay for my equipment 100 % though dad helps me out with materials. On to my dad, him and I are the only people that touch my truck. I've been a basshead since I was little because of him. He used to be a professional installer (before I came along) so I was bumping in the womb in his show car. He helps me out a lot with installs and I try to learn as much as I can so that someday maybe I can know more than him some day. (I don't think it'll happen) Anyways, enough with that, let's get y'all some pictures!
Truck 2002 Ford F-150 Supercrew
Equipment:
XS Power D3400
SkyHigh 1/0 & 4 Gauge Wire and Fusing
Big 3
AQ 2200d
AQ 200.2
2 Soundqubed HDS315's in a Ram-Designs 4th
6 Soundqubed Pro Audio 6.5's
2 Soundqubed Pro Audio Tweets 40 Sq ft of Soundqubed Q-Mat

Hi fellow members!
I have an 04 quest looking to do a 4th order in the trunk.
I have 4 american bass XFL 12s.
looking for a 2:1
Would be greatful for some help thanks!
So far i have
sealed section = 3.315
ported = 6.63
port area = 99.45?
I'm having a bit of an issue with the port size
what tuning do you guys recommend?
along with dimensions?

Hey guys, I'm trying to build a fourth order for 4 soundqubed hds200 15's. Need help because I've never built a box like this before and I want some input on what people think on what I've got so far. On the ported side I plan on giving the woofers 4.5 cubic ft each so in all a total of 18. And on the sealed side I plan on giving them 1.5 cubic ft each so a total of 6. I wanted to tune it to around 32 hz so for the port I plan making an 11x11 square port that's 3.25 deep. So give me some feed back on whether this sounds good or bad haha, thanks.

Any input is appreciated, thanks Vehicle : 2000 Eclipse Space available : ( Depth 22 x Width 32 x Height 16.5) Subwoofer make and model: 1 Dc XL m2 15 on 3k Type of Port (Kerfed, Slot, Aero, etc.): Need help! Everyday Music Tuning Freq : 31-32 Hz ? Volume : 4 cubes? Dc says Atleast 3 Questions: Need help on box design. 4th order or aero port box? the sub needs too face forward (unless 4th order). What will be a better design for the sub? How many aero ports and what size would be needed? Can the port be forward facing? external aero port? can the port and sub face forward if not sealed but a good fit? this the same car with a side firing port https://www.youtube.com/watch?v=ELV1...lbN7SQ&index=7 . This is with the external port and forward firing https://www.youtube.com/watch?v=MWKRw-zxjPo . Feel comfortable with building any design and have the tools to do so (or atleast try) Thanks for your time!

Hey everyone its been a while (like a year, seems like a while to me) since ive installed anything into my car. I have a 12 in p3 I would like to put into a 4th order bandpass box in the trunk of my car. After reading about 4th orders I would like to go with a 1:2 ratio. The sealed side being .83 cu ft and the ported side being 1.62 cu ft after displacement. Tuned to about 47 hz with about 15 in of port per cube via a slot port. This will be the first 4th order I have built or designed so if I may have this all wrong. Just wanted to see what you guys think about the idea and specs of the box?

Just bought the Suburban about 2 weeks ago. All the bag work was done when i got it. Its on 24s and the compressor for the bags is belt driven. Its already a head turner seeing something this big going down the road with front all the way up and the back down lol but now its time for the audio.
Im doing 6 Sundown X 15s in a 4th order back at the c pillar
Im gonna run 3 of the new Sundown SCV amps(not sure which ones yet) but gonna use some cheapos till there out and i have the cash.
I had a big build in my car and sold most of everything so now i also gotta slowly buy some electrical back. I just have 2 xs D3100 for now and stock alt
I already have the subs. Pics of the Suburban:
At Sundown Headquarters
Picking up subs from dealer

So i have some plans for my truck for this year. Back seat is coming out, & i'd like to get 2 HDC3 12"s or 15" inch subs from soundqubed.
So i need your guys help with a couple things, Who designs the best 4th Order's on this site? & Also who builds them good in the Socal area. I'd love to help with the box build but have nothing to cut wood & no experience with it, so doing a 4th order for a first box doesn't seem like i'd get what i want out of it.
The measurements i have to work with because i don't want to go above the window line is roughly 38" from side to side, 28" from front to back, & 30" tall after a false floor. //
As stated above i'd prefer to have the 12" subs, but am open to going to 15" subs. I listen to a wide variety of music, but mostly Underground Hip Hop & EDM.
As for goals with this box i just want it to hit a wide variety of notes with a nice punch. More so musical then Loud, dont plan on metering or anything of that nature.
Open to suggestions, & any help would be appreciated, Thanks SMD

im going to order a AMERICAN BASS DX154. bc i want to make a 4th order for the frist time.
its going to go in my den. im going to use it as a surround sound subwoofer
im trying to get it as musical and spl as posibile
its beening powered by a crown xls1000
can any one give me an idea of how big of a box i would need or design thanks
max dimensions are 40 wid x 28 deep x 36 tall
tunning around low 30s

whats up guys, long time form creeper 1st time post, so I picked up some brand new 2014 Kicker L7's today and a Hifonics Zeus 3200.1... I had a Brutas and a Addictive audio V2 12 in a 4th order.. My question is is a 4th order possible for 2 12" L7 in a 2012 impala I already have top deck cut for old 4th order 6.5x9 port, I know new port will be MUCH bigger but im lost on building this box I cant find any answers or ppl who have done it I want SPL not Quality... ANY help or ideas creating this box would be great! thanks guys.